CharacterMixer:
Rig-Aware Interpolation of 3D Characters

Xiao Zhan1, Rao Fu1, Daniel Ritchie1
1Brown University

Eurographics 2024

Teaser Figure

Abstract

We present CharacterMixer, a system for blending two rigged 3D characters with different mesh and skeleton topologies while maintaining a rig throughout interpolation. CharacterMixer also enables interpolation during motion for such characters, a novel feature. Interpolation is an important shape editing operation, but prior methods have limitations when applied to rigged characters: they either ignore the rig (making interpolated characters no longer posable) or use a fixed rig and mesh topology. To handle different mesh topologies, CharacterMixer uses a signed distance field (SDF) representation of character shapes, with one SDF per bone. To handle different skeleton topologies, it computes a hierarchical correspondence between source and target character skeletons and interpolates the SDFs of corresponding bones. This correspondence also allows the creation of a single "unified skeleton" for posing and animating interpolated characters. We show that CharacterMixer produces qualitatively better interpolation results than two state-of-the-art methods while preserving a rig throughout interpolation.

Interpolation in rest pose

Interpolation during animation

Teaser Video

Citation

@misc{zhan2024charactermixer,
    title={CharacterMixer: Rig-Aware Interpolation of 3D Characters}, 
    author={Xiao Zhan and Rao Fu and Daniel Ritchie},
    year={2024},
    eprint={2402.15580},
    archivePrefix={arXiv},
    primaryClass={cs.GR}
}